Which one has greater carbon emissions per unit of electricity, nuclear power or thermal power?

Thermal power is larger.

In the process of power generation, nuclear power does not burn fuel. It is the nuclear material that undergoes fission to generate energy to generate electricity. Thermal power plants burn coal, and burning coal will produce carbon dioxide.

So, simply considering the power generation process, nuclear power has no carbon emissions, while thermal power does, and it is very high. Therefore, thermal power has greater carbon emissions.